Light-sensitive color photographic material with indazolone color couplers

ABSTRACT

INDAZOLONES HAVING A CARBAMYL SUBSTITUTION IN THE BENZENE RING MAKE PARTICULARLY DISIRABLE MAGNETA-FORMING COLOR COUPLERS FOR COLOR PHOTOGRAPH.

United States Patent 3,782,956 LIGHT-SENSITIVE COLOR PHOTOGRAPHIC MA- TERIAL WITH INDAZOLONE COLOR COUPLERS Immo Boie, Cologne, Walter Schulte, Opladen, Willibald Pelz and Fritz Nittel, Cologne, and Friedrich-Wilhelm Kunitz, Leverkusen, Germany, assignors to Agfa- Gevaert Aktiengesellschaft, Leverkusen, Germany No Drawing. Filed July 15, 1971, Ser. No. 163,044 Claims priority, application Germany, July 18, 1970, P 20 35 725.9 Int. Cl. G03c N40 US. Cl. 96-100 4 Claims ABSTRACT OF THE DISCLOSURE Indazolones having a carbamyl substitution in the benzene ring make particularly desirable magenta-forming color couplers for color photography.

The present invention relates to a light sensitive color photographic material comprising at least one silver halide emulsion layer which contains indazolone derivatives as couplers for producing the magenta partial image.

It is known to produce colored photographic images by chromogenic development, i.e. by developing with suitable color developers silver halide emulsion layers which have been exposed imagewise and performing this development in the presence of suitable color couplers, the oxidation product of the developer produced in the areas corresponding to the silver image reacting with the color coupler to produce a dye image. The color developers used are generally aromatic compounds which contain primary amino groups, in particular those of the p-phenylenediamine type.

The color couplers and the dyes which are produced from them by chromogenic development must satisfy numerous requirements in practice. The color coupler should have a very high rate of coupling with the oxidation product of the color developer, and both the color coupler and the dyes produced from them should be sufiiciently stable to light, elevated temperature and moisture. This applies both to fresh material and to material which has been processed. For example, the residual coupler still present in the image whites of the processed material must not undergo yellowing. In addition, the dyes should be sufficiently stable to gaseous reducing or oxidizing agents, and they must be fixed in a difiusionfast form in the image layer, and on chromogenic development they should be deposited as a very fine grain. Furthermore, the mechanical properties of the layers must not be impaired by the color couplers. Lastly, the dyes produced on chromogen'ic development of the color couplers should have a suitable absorption curve with a maximum corresponding to the color of the desired partial image with as little side absorptions as possible. In the ideal case, a magenta dye should absorb green light practically completely and be substantially permeable both to blue and to red light.

The magenta-forming couplers used, i.e. the color couplers suitable for producing the magenta color image, are generally compounds which may be derived from 2-pyrazolone-5. Indazolone derivatives are also occasion- 3,782,956 Patented Jan. 1, 1974 ally used as magenta-forming couplers; see German patent specification 918,484, Pat. No. 3,199,983 and British Pat. 1,182,202. The disadvantages of indazolone couplers lie in the low coupling intensity compared with that of pyrazolone couplers and in the fact that these couplers undergo brown discoloration when stored for some time in daylight. It is especially this last mentioned characteristic which severely limits the use of indazolone couplers for the production of images on paper or on any other color photographic materials which are exposed to daylight. Another disadvantage is that the strongly polar structure of the indazolone nucleus causes compounds having a high melting point to be formed even in the case of derivatives with non-polar substituents. No indazolone couplers which are readily soluble in ethyl acetate, methylene chloride and similar organic solvents have so far become known. This characteristic combined with the usually high melting points has hitherto made it difiicult to use indazolone couplers in photographic layers.

It has now been found that indazolone couplers which carry a carbamyl group in the benzene ring of the indazolone group have exceptionally advantageous properties both as regards improved emulsifiability and as regards their reduced tendency to undergo brown discoloration in daylight.

This invention therefore relates to a light-sensitive photographic material comprising at least one silver halide emulsion layer, characterized by containing magenta-forming coupler of the following formula:

R1 4 o j; e 1 N-H R: N/

wherein R represents hydrogen or alkyl having up to 18 C atoms,

such as methyl, ethyl, hexadecyl. or octadecyl, optionally substituted with aryl, e.g. benzyl or phenylethyl;

R represents alkyl having up to 20 C atoms and preferably at least 12 C atoms, e.g. dodecyl or octadecyl, cycloalkyl such as cyclohexyl, or aryl, such as phenyl;

X represents hydrogen, halogen such as chlorine or bromine, alkyl or alkoxy having up to 20 C atoms.

For the purpose of obtaining sufiicient resistance to difiusion of the couplers, it is preferred to use those indazolone derivatives in which at least one of the radicals R and R contains a long chain aliphatic group having at least 12 C atoms. R and R may in turn be substituted, e.g. with ether, carbamyl, acylamino or sulf- 3,782,956 amido groups or with groups which render the c'ouplers The following couplers have beeii fdund tb b espe- .a a -S9luble,,such as COOH or SO H. r i cially suitable (F. indicating the melting pQint):: .i

CHz-CH (2) S 0311 F. 239-241 C.

(3) H V F. 115 C.

C15H37NC -C=O 7 I l hiss- 135 SOzH The indazolone couplers according to the invention are generally prepared from the corresponding indazolone carboxylic acids from which the corresponding acid chlorides are prepared. It is necessary first to protect the indazolone system; this is achieved by introducing acetyl groups which can easily be split olf subsequently. The color couplers according to the invention are then obtained from the acid chlorides by reacting them with suitable primary or secondary amines. The preparation will now be described with the aid of examples.

4 (N OCTADECYL N 8 PHENYLETHYL- CARBAMYL)-INDAZOLONE (COUPLER 1) Indazolone-4-carboxylic acid 300 g. of 3-nitro-orthophthalic acid are neutralized with concentrated sodium hydroxide solution in 2 l. of water and hydrogenated in the presence of palladium charcoal at 50 atmospheres above gauge and 80 C. The reaction product is filtered, 100 g. of NaNO are added, and the reaction mixture is then stirred into 700 ml. of concentrated hydrochloric acid at 5 to 10 C. This reaction mixture is then stirred for one hour at 10 C., 150 g., of NaCl are added; and the precipitate of diazonium salt is removed by suction filtration and introduced into a solution of 750 g. of SnCl -2H in 1000 ml. of concentrated hydrochloric acid at to C. After one hour, the hydrazine salt is removed by suction filtration and introduced into a solution of 7 50 g. of SnCl -2H O in 1000 ml of concentrated hydrochloric acid at 5 to 10 C. After one hour, the hydrazine salt is removed by suction filtration, suspended in 800 ml. of half concentrated hydrochloric acid and heated under reflux for 1% hours. After cooling, the product is removed by suction filtration and washed with dilute hydrochloric acid and Water. Yield 120 g. (48%) of indazolone-4-carboxylic acid; M.P. 290 to 300 C.

F. ca. 280 0.

Diacetyl-indazolone-4-carboxylic acid 50 g. of indazolone-4-carboxylic acid are heated to boiling for one hour in 300 ml. of acetic anhydride. After cooling, the product is removed by suction filtration, triturated with ether, again filtered through a suction filter, washed with ether and dried. Yield 58 g. (77%;) of diacety1-indazolone-4-carboxylic acid; M.P. 230 C.

Diacetyl-indazolone-4-carboxylic acid chloride 58 g. of diacetyl-indazolone-4-carboxylic acid and 300 ml. of thionyl chloride are stirred together and heated to boiling. After the addition of a few drops of dimethyl formamide, heating is continued until the evolution of hydrogen chloride ceases. The excess thionyl chloride is then removed under reduced pressure. The crystalline acid chloride remains behind. M.P. 120 C. Yield almost quantitative.

Coupler 1 71 g. of octadecyl-fl-phenylethylamine are dissolved in 800 ml. of anhydrous tetrahydrofuran at elevated temperature. ml. of triethylamine are added, and 50 g. of finely powdered diacety1-indazolone-4-carboxylic acid chloride are then added gradually. The reaction mixture is heated to boiling for 3 hours and precipitated with a mixture of ice and concentrated hydrochloric acid. The oil which separates is taken up in ether and the ethereal phase is washed with water, dried over sodium phosphate and concentrated by evaporation. The oily residue is heated to boiling in 2 N NaOH for 7 minutes and precipitated in ice/HCl. The resulting aqueous phase is decanted from the viscous oil which has formed. The viscous oil is taken up in hot ethyl acetate which is then shaken up in 2 N soda solution and water, separated and dried at elevated temperature with CaCl The liquid is then filtered off and placed in an ice bath to precipitate the coupler. After hours, itis isolated by suction filtration. Yield: 60 g. of Coupler 1; M.P. 68 C.

ing to the invention which are so-called emulsifying coum lers hydro omma d arsinsq in 4-(N-OCTADECYL N B SULFOPHENYLETHYL- CARBAMYL)-INDAZOLONE (COUPLER 2) 88 g. of Coupler 1 are introduced into a mixture of 400 ml. of concentrated H 80 and 100 ml. of 20% oleum and cooled with ice atthe same time. The reaction mixture is then stirred at room temperature for 6 hours and the product is precipitated with a little ice. The precipitate is removed by suction filtration, washed with ice water and dried on clay. The dry coupler is suspended in hot ethyl acetate, a little methanol is added, the reaction mixture is cooled and the product is removed by suction filtration and washed with petroleum ether. Yield: 48 g. of Coupler 2; M.P. 239-241 C.

4 (N OCTADECYL N B PHENYLETHYLCAR- BAMYL)-5-CHLORO'-INDAZOLONE (COUPLER 4) I 4-chloro-2,3-dimethyl-N-acetyl-aniline 163 g. of 2,3-dimethyl-N-acetyl-aniline are dissolved in 1600 ml. of glacial acetic acid and 100 ml. of water, and 71 g. of chlorine are introduced at 0 C. After one hours stirring, the reaction mixture is introduced into water and cooled and the product is removed by suction filtration. Recrystallization from methanol/water (1:1) yields 4-chloro-2,3-dimethyl-N-acetylaniline.

3-acetamino-6-chloro-orthophthalic acid 100 g. of the above product are suspended in 3.5 l. of water, and heated to 60 C. after the addition of 125 g. of MgSO 400 g. of KMnO, are then added gradually in small portions. The reaction temperature is maintained at 75 to 80 C. for 8 hours. The reaction mixture is decolorized with Na SO and filtered hot through a'suction filter. The precipitate is washed with a little hot water and the filtrate is concentrated to half its volume by evaporation and acidified with hydrochloric acid. After cooling, it is filtered through a suction filter. 100 g. of B-acetamino-6chloro-orthophthalic acid are obtained. This product can be' recrystallized from water. M.P. 160 to 163 C. Subsequent working up of this product to 5-chloro-indazolone-4-carboxylic acid is carried out by the method described for Coupler 1. v

The new magenta-forming couplers are found to'be superior to the known indazolone couplers in two respects. The stability is considerably improved, especially the stability to light, and the new couplers have a greatly reduced tendency to undergo brown discoloration in daylight. 'If the carbamyl radical is in the 4-position of the indazolone group, brown discoloration is completely elimiated. Furthermore, the emulsifiability is substantially improved provided the molecule does not contain any groups which would render it soluble in alkalies.

The new magneta dyes obtained from the new color couplers with N,N-diethyl-p-phenylenediamine or N-butyln-w-sulfobutyl-p-phenylenediamine as developer have good spectral properties. The side densities in the blue region and especially in the red region are very slight.

The compounds according to the invention thus represent valuable color couplers which on chromogenic devel-' opment yield magenta dyes which have excellent characteristics of stability. They are eminently suitable for use in light sensitive silver halide emulsion layers of color photographic single layered or multilayered materials; The magenta-forming couplers need not necessarily be incorporated in the light sensitive layers but may be accommodated in a layer of binder adjacent to a light sensitive silver halide emulsion layer.

The magenta-forming couplers according to the invention may be incorporated with the silver halide emulsion by one of the known methods or they may be incorporated with another binder mixture. Those couplers accorda known manner by dissolving them'in suitable organic solvents, e.g. in esters of aliphatic carboxylic acids and especially in ethyl acetate or in methylene chloride and emulsifying this solution in the silver halide emulsion which is ready for casting. The method may occasionally be advantageously modifiedby using oily coupler solvents, so-called oilformers, at the same time. This process has been disclosed in U.S. Pat. 2,304,940 and 2,322,027.

If the couplers are alkali-soluble, they are added. to the casting solutions for the photographic layers in the form of an aqueous/alkaline solution. 7

Suitable light sensitive emulsions are emulsions of silver halides such as silver chloride, silver bromide or mixtures thereof, optionally with a small silver iodide content of up to 10 mols percent, in one ofthe commonly used hydrophilic binders such as protein, especially gelatin, polyvinyl alcohol, polyvinylpyrrolidone, cellulose derivatives such as carboxymethyl cellulose, or derivatives of alginic acid.

The emulsions may also be'chemicallysensitized, e.g. by adding compounds which contain sulfur, for example allylisothiocyanate, allylthiourea or sodium thiosulfate, at the stage of chemical ripening. Reducing agents, e.g. the tin compounds described in Belgian Pat. 493,464, or 568,- 687, or polyamines such as diethylenetriamine or 'aminomethanesulphinic acid derivatives may also be added as chemical sensitizers, e.g. according to Belgian Pat. 547,323. 1

Noble metals such as gold, platinum, palladium, iridium, ruthenium or rhodium, and noble metal compounds are also suitable for use as chemical sensitizers. This method of chemical sensitization has been described in the article by R. Koslowsky, Z. Wiss, 'Phot. 46, 65-72 molecular weight of between 1000 and 20,000, or .with

condensation products of alkyleneoxides and aliphatic alcohols, glycols or cyclic dehydration products of fhe'xitols with alkyl-substitutedphenols, aliphatic carboxylic acids, aliphatic amines, 1 aliphatic 'diamines' or amides. The condensationpproducts haveja molecular weight flat least 700 and'preferably more thajri'lOOOJThesle s en'sitiz B may, of course, be combined for the purpose or" achi ing special eifects, as described in Belgian Pat. 537,2 I i in British patent specification 727,982.,

The emulsions which contain color couplers'ma'y also contain spectral sensitizers, e.g. the usual" monomethine or polymethine dyes such as basic or acid'cyanines, hemicyanines, streptocyanines, merocyanines, oxonoles, hemioxonoles, styryl dyes, including also methine dyes which have three or more nuclei, for example rhodacyanines or neocyanines.'Sensitizers of I this type have been described, for example, in the workibyp F. M, Hamer.The Cyanine Dyes and Related Compounds"( 19 64) Interscience Publishers, John Wiley and Sons. The colorvco u plers according to the invention are, however, preferably used in those emulsions" which are sensitized to green light.

The emulsions may contain the usual stabilizersgelg. homopolar, or salttypev compoundsof mercury ...which have jaromatic 'orilieterocyclic rings, .such as 'mercaptotrb azoles, simple mercury salts, sulfonium, mercury double salts and other mercury compounds. Azainderies are also .suitable stabilizers, especially tetra ,or, pentaazaindenes The emulsions may be hardened in the usual manner, for example with formaldehyde or halosubstituted aldehydes which contain a carboxyl group, such as mucobromic acid, diketones, methanesulfonic acid esters or dialdehydes.

The usual color developers are used for producing the magenta part of the image, eg the usual aromatic compounds of the paraphenylene diamine type containing at least one primary amino group. N,N-dimethyl-p-phenylenediamine, N,N-diethyl-p-phenylenediamine, monomethyl-p-phenylenediamine and N-butyl-N-w sulfobutyl-pphenylenediamine are examples of suitable color developers. Other suitable color developers have been described, for example, in J. Am. Chem. Soc. 73, 3100 to 3125 (1951). It is preferred to use those developers in which the two positions adjacent to the primary amino group are unsubstituted.

EXAMPLE 1 10 g. of Coupler 1 are dissolved in 50 ml. of ethyl acetate, and after the addition of 10 g. of dibutylphthalate the solution is emulsified at 60 C. in 200 ml. of a 5% gelatin solution which contains 1.6 g. of the sodium salt of dodecyl benzene sulfonic acid. The emulsion is then mixed with 850 g. of a 7.5% aqueous gelatin solution which contains 19.25 g. of silver bromide in a dispersed form, and this mixture is then diluted with water until the viscosity is suitable for casting, and it is then cast on a transparent layer support. After drying, the film is exposed behind a grey wedge and developed in a color developer of the following composition:

6 g. of N-butyl-N-w-sulfobutyl-p-phenylenediamine, 4 g. of hydroxylamine hydrochloride,

4 g. of anhydrous sodium sulfite,

1 g. of potassium bromide,

100 g. of potassium carbonate,

made up to 1000 ml. with water.

The obtained color wedge is exposed to daylight together with a color wedge obtained from Coupler l of U.S. Pat. No. 3,199,983 which has been developed in the same manner. Whereas the color wedge obtained from Coupler 1 of U.S. Pat. No. 3,199,983 showed severe brown discoloration after only a few days, the color wedge according to the invention had clear whites even after 3 weeks.

EXAMPLE 2 18 g. of Coupler 2, 50 g. of a 33% methanolic solution of pentadecylene succinic acid and 1 g. of his- (2ethyl) hexyl ester of sulfosuccinic acid are dissolved in 40 ml. of methanol, 240 ml. of water and 24 ml. of 5 N NaOH and stirred into 1 kg. of green sensitized silver halide emulsion. The resulting emulsion contains 0.33 mol of silver bromide, 0.0075 mol of silver iodide and 90 g. of gelatine per kg. Subsequent working up is carried out as described in Example 1. A magenta wedge which has a blue tinge is obtained. When the whites of this wedge are tested for their reaction to daylight, the same result is obtained as in Example 1.

EXAMPLE 3 wherein R represents hydrogen or alkyl with up to 18 C atoms;

R represents alkyl with up to 20 C atoms, cycloalkyl or aryl; and

X represents hydrogen, halogen, alkyl or alkoxy with up to 20 C atoms.

2. Material according to claim 1, wherein at least one of R and R contains a hydrocarbon chain with at least 12 C atoms.

3. Material according to claim 1, characterized in that the substituent is in the 4-position of the indazolone group.

4. Material according to claim 1 in which the coupler is selected from the class consisting of couplers 1 through 10.

References Cited UNITED STATES PATENTS 2,866,706 12/1958 Woolley 96-100 2,872,317 2/1959 Woolley 96-56.5 2,673,801 3/1954 Jennen 96100 3,199,983 8/1965 Koepke etal. 96-100 NORMAN G. TORCHIN, Primary Examiner R. L. SCHILLING, Assistant Examiner UNITED STATES PATENT OFFICE V CERTIFICATE OF CORRECTION pajent 3,782,955 Dated Jan. 1', 197

immo Bole eta].

Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, formula 11, the formula should read as follows:

Column 5, formula 12', I the formula should read as follows:

Signed and, sealed this 17th day' of December 1974.

(SEAL) Attest: V

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents FORM Po-105o (10-59) USCOMM-DC GONG-P69 u.s. oovznuunn' nim'nuo ornca: nu o-Jol-su.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,782,956 Dated Jan. l,' .197

Inventor(s) Immo B018 81.. 8.1

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, formula 11, the octadecyl group should be connected to the nitrogen atom as follows:

Column 5, formula 12, the octadecyl group should be a connected to the nitrogen atom as follows:

Column '4, formula 7, the left side of the formula should read as follows: a a

Signed and sealed this 20th day of August 197% (SEAL) Attest: v

MCCOY M. GIBSON, JR, c. MARSHALL DANN Attesting Officer Commissioner of Patents 

